One more thing...

Could I in theory use the components featured in this tutorial…
https://learn.sparkfun.com/tutorials/internet-datalogging-with-arduino-and-xbee-wifi
…minus the other sensors used and just add an appropriate humidity sensor, to create my project? It even mentions the possibility of using plot.ly graphs. It seems I could also download the data files onto spreadsheets which I could use for creating a UI with visual basic?

Yes you could go that rout but that would be more expensive and more complex than the rout I suggested of using an XBee Grove board with Matching Grove sensors.

OK. Thanks for your help and patience.

Ben